The use of single application, disposable medical devices is widespread among hospitals, clinics, and doctors' offices. This insures that each patient receives a workable, sterile device for each treatment, and the risk of spreading microbes between devices is eliminated. However, disposable medical devices are frequently very costly, thereby dramatically increasing the cost of medical treatments each time a new device is employed in a medical procedure.
It has been discovered that disposable medical products could be a key area for cost savings if changes in current practices and procedures relating to the use of disposable medical products could be effected. If devices initially designed for single application could be re-used, the price per use would fall, the overall cost of the particular procedure would drop, and if the volume of procedures in a medical facility remained constant, the cost would drop.
Cardiac catheters are one such class of disposable, single use devices which have been examined for possible re-usability. Common cardiac electrode catheters used in electrophysiologic treatment comprise a plurality of sensing or signal generating electrodes at one end of the catheter, with wires running internally through the length of the catheter and connected between each individual electrode at the opposite or connective end of the catheter. Some types of catheters used in such treatment include standard quadripolar catheters, bipolar catheters, tripolar catheters, and custom-made quadripolar catheters. The connective end of the catheter may comprise socket connecting elements individually attached to each of the wires leading from the electrodes. Alternately, the connective end of the catheter may comprise a plurality of wire ends leading from the catheter. In both situations, the socket elements or wires at the connective end of the catheter are adapted to be placed in electrical contact with a control device that transmits the electrical signals generated by the electrodes to a device for displaying the signal, such as a sinusoidal wave form, ultrasound image, numerical display, or the like. Cardiac catheters of the type mentioned above are usually non-lumen, woven Dacron.RTM., multi-electrode pacing catheters.
Studies have shown that two primary considerations in the re-use of cardiac catheters are cleaning and sterilization to prevent the risk of spreading disease-bearing microbes, and the functional reliability of the catheter following repeated use. Sterilization just prior to re-use has been found to rid the catheter of microbes, whereupon when properly and rigorously cleaned, re-use of catheters did not create an obvious increase in the risk of infection. However, it has also been found that repeated sterilization may make the catheter and its electronic components fragile, thereby possibly leading to the deterioration of the mechanical and electrical properties of the catheter.
Currently, catheters to be re-used are subjected to several checks to determine their functional reliability. For example, a visual check is made to determine if any part of the catheter is cracked or too stiff to be used properly. This visual check will also reveal any outward physical damage to the tip or the electrodes of the catheter. Also, records are currently kept on the number of times a catheter has been re-used, and limits are placed on the maximum number of uses of a particular catheter.
As part of determining the functional reliability of the catheter prior to their sterilization and re-use, catheters presently are tested for electrical continuity, wherein a standard ohmmeter is used manually to measure resistance. This test requires a technician to hold one probe of the ohmmeter against a socket or wire at the connective end of the catheter, and the other probe against one of the electrodes at the electrode end of the catheter. The probe used at the electrode end of the catheter is serially brought into contact with each of the electrodes while holding the other probe in place against one of the sockets or wires at the connective end of the catheter. If there is continuity between the electrode and the socket or wire being contacted by the other probe, the ohmmeter will display the resistance value indicating electrical continuity in that wire. This test procedure is repeated for each wire in the catheter. The above described test procedure usually requires more than two hands to adequately hold the probes in place and to manipulate the probes properly, and becomes rather cumbersome to adequately complete. Also, when attempted manually, the probes may not make proper contact with the elements against which they are placed, possibly resulting in false positive or negative readings. A false negative reading may result in discarding a perfectly re-usable, and expensive, catheter. A false positive reading may result in inserting a defective catheter into the artery of a patient.
Therefore, an object of the present invention is to provide a testing apparatus for cardiac catheters which enables a technician to rapidly and accurately test the catheter for electrical continuity.
Another object of the present invention is to provide a testing apparatus for cardiac catheters which mechanically and positively maintains a connection between the connective end of the catheter and one of the probes of an electrical continuity testing device while a technician can readily manipulate the other probe of the testing device between the various electrode elements of the catheter.
A further object of the present invention is to provide a cardiac catheter testing apparatus having a support structure which maintains a probe of an electrical continuity testing device in electrical contact with one socket or wire formed in the connective end of the cardiac catheter, thereby enabling a technician to readily and accurately manipulate a second probe of the electrical continuity testing device against the electrodes at the electrode end of the cardiac catheter.
An additional object of the present invention is to provide a multi-electrode cardiac catheter testing apparatus having a support structure which forms an electrical contact path between each of the sockets or wires forming the connective end of the cardiac catheter and one of a plurality of receptacles. The receptacles are adapted to removably maintain a probe of an electrical continuity testing device in electrical contact with one of the sockets or wires of the cardiac catheter while another probe of the continuity testing device is manually brought into sequential contact with each of the multiple electrodes formed as part of the catheter.